As shown in FIG. 9, in Japanese Patent Publication No. 2770389 (patent document 1), a charging device comprising wireless headphones 1 and a transmission device 2 is disclosed. An engaging recess 3 is formed at an upper end of a cabinet of a transmission device 2. The dimensions of this engaging recess 3 are substantially the same as the width of a hanger section 4 of the headphones 1 so as to receive a protruding section 5 at a substantially central portion of the hanger section 4.
When the headphones 1 are mounted on the transmission device 2 so that the protruding section 5 of the hanger section 4 inserts into the engaging recess 3, pins 6 erected at the engaging recess 3 are inserted to within holes 7 of the protruding section 5 so as to make contact with electrodes within the holes 7. In this way, a secondary battery 8 provided within the headphones 1 is charged by a power supply circuit on the side of the transmission device 2.
Here, light-emitting elements 9 are provided at the transmission device 2 and light-receiving elements 10 are provided at the headphones 1. Therefore, after the secondary battery 8 of the headphones 1 is charged by this transmission device 2, while the headphones are detached for use, it is possible for signals to be transmitted to the light-receiving elements 10 of the headphones 1 from the light-emitting elements 9 of the transmission device 2 using infrared rays etc. It is therefore possible for audio to be played back using the headphones 1 without employing a signal cable (refer to patent document 1).
Further, in Japanese Utility Model Laid-open Publication No. H7-22955 (Japanese Patent Publication 2), there are disclosed wireless headphones employing a secondary battery as an operation power supply. It is then possible to open and close charging terminals for charging the secondary battery using an opening and closing body interlocking with an operation section of a switch for switching over the operating state of the headphones. This makes it possible to prevent hair and skin from making contact with the charging terminals by opening and closing the charging terminals using the opening and closing body when the headphones are worn on a person's head and therefore prevent corrosion of and defective contact with the charging terminals.
It is preferable for the operation of charging wireless headphones with a secondary battery built-in to be straightforward. Patent document 1 and patent document 2 described above disclose charging devices where the secondary battery does not have to be removed from the headphones where charging is possible as a result of mounting the headphones on the battery charger. With these charging devices of the related art, charging is carried out by making contact between charging pins 6 and electrodes as a result of utilizing the weight of the headphones 1. It is therefore not possible to ensure a contact pressure that is greater than the dead weight of the headphones. This has the disadvantage that the connection of the pins 6 is not always stable. There is also a problem that fine adjustment is necessary in order to correctly line up the positions of the terminals on the headphone side and the pins on the side of the battery charger during the charging operation.
In order to resolve the aforementioned problems, it is advantageous for the present invention to provide a charging device capable of ensuring sufficient connection pressure in excess of the weight of wireless apparatus such as headphones etc. that does not require fine adjustment in order for electrodes to make appropriate contact with a connection member.